The new tab page can be changed by switching a setting or using an extension. Let's try the setting first, and then if necessary, check extensions.

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste newtab and pause while the list is filtered

(3) Double-click the browser.newtab.url preference and enter your preferred page:

• Page thumbnails (default) => about:newtab
• Blank tab => about:blank
• Built-in Firefox home page => about:home
• Any other page => full URL to the page

Press Ctrl+t to open a new tab and verify that it worked. Fixed?

Three things to look out for:

• If Firefox will not save any changes to this setting, you may have a program named Search Protect that you need to uninstall through the Windows Control Panel, Add/Remove Programs.

• If Firefox ignores the setting, one of your extensions may be overriding it. Please open the Add-ons page, Extensions section, and cast a critical eye on what's there. As a first approximation, try disabling everything you will not use in the next 24 hours. You can open the page using either of the following, then click "Extensions" in the left column:
  • Ctrl+Shift+a
  • "3-bar" menu button (or Tools menu) > Add-ons

• If the change works for the rest of your session but at the next startup is back to blank, you might have a user.js file in your personal Firefox settings folder (your Firefox profile folder). This article describes how to track down and remove the file: How to fix preferences that won't save. Some utility programs like Advanced SystemCare have a feature to revert your settings to an earlier state between sessions ("Surfing Protection"). That's another thing to check for if you keep losing your settings changes.

Any luck?

Also, as a quick way to open your home page in a new tab, you can either:

• hold down Ctrl and click the Home icon on the toolbar
• "middle-click" the Home icon on the toolbar (click using the mouse scroll wheel)

Thanks. The fix work as suggested. I stopped an install from CNET for a JPG-PDF converter. Afterwards, each time I opened a new tab in Firefox, I got a trvio search engine page. Had to find & delete Search Protect which this search engine also installed.